Scaling Analysis of Thermal Hydraulics Phenomena in the Nuclear Reactor Vessel Downcomer during the Reflood Phase of LBLOCA

대형냉각재 상실사고 재관수 기간 동안, 차세대 원자로 강수부 내의 열수력 현상 모의를 위한 실험장치 척도해석

As one of the advanced design features of the Korea next generation reactor, direct vessel injection (DVI) system is being considered instead of conventional cold leg injection (CLl) system. It is known that the DVI system greatly enhances the reliability of the emergency core cooling (ECC) system. However, there is still a dispute on its performance in terms of water delivery to the reactor core during the reflood period of a large-break loss-of-coolant accident (LOCA). Thus, experimental validation is under progress. In this paper, a new scaling method, using time and velocity reduced linear scaling law, is suggested for the design of a scaled-down experimental facility to investigate the direct ECC bypass phenomena in PWR downcomer.